TY - JOUR
T1 - Naturally Occurring Radioactive Materials in Uranium-Rich Coals and Associated Coal Combustion Residues from China
AU - Lauer, Nancy
AU - Vengosh, Avner
AU - Dai, Shifeng
N1 - Funding Information:
This research was supported by the National Key Basic Research Program of China (no. 2014CB238902) and the National Natural Science Foundation of China (no. 41420104001). The authors would also like to thank Dr. James Kaste at the College of William and Mary for laboratory use. We also thank Dr. Huaming Guo from China University of Geosciences for providing the loess and fly ash samples from Beijing area.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/11/21
Y1 - 2017/11/21
N2 - Most coals in China have uranium concentrations up to 3 ppm, yet several coal deposits are known to be enriched in uranium. Naturally occurring radioactive materials (NORM) in these U-rich coals and associated coal combustion residues (CCRs) have not been well characterized. Here we measure NORM (Th, U, 228Ra, 226Ra, and 210Pb) in coals from eight U-rich coal deposits in China and the associated CCRs from one of these deposits. We compared NORM in these U-rich coals and associated CCRs to CCRs collected from the Beijing area and natural loess sediments from northeastern China. We found elevated U concentrations (up to 476 ppm) that correspond to low 232Th/238U and 228Ra/226Ra activity ratios (â‰1) in the coal samples. 226Ra and 228Ra activities correlate with 238U and 232Th activities, respectively, and 226Ra activities correlate well with 210Pb activities across all coal samples. We used measured NORM activities and ash yields in coals to model the activities of CCRs from all U-rich coals analyzed in this study. The activities of measured and modeled CCRs derived from U-rich coals exceed the standards for radiation in building materials, particularly for CCRs originating from coals with U > 10 ppm. Since beneficial use of high-U Chinese CCRs in building materials is not a suitable option, careful consideration needs to be taken to limit potential air and water contamination upon disposal of U- and Ra-rich CCRs.
AB - Most coals in China have uranium concentrations up to 3 ppm, yet several coal deposits are known to be enriched in uranium. Naturally occurring radioactive materials (NORM) in these U-rich coals and associated coal combustion residues (CCRs) have not been well characterized. Here we measure NORM (Th, U, 228Ra, 226Ra, and 210Pb) in coals from eight U-rich coal deposits in China and the associated CCRs from one of these deposits. We compared NORM in these U-rich coals and associated CCRs to CCRs collected from the Beijing area and natural loess sediments from northeastern China. We found elevated U concentrations (up to 476 ppm) that correspond to low 232Th/238U and 228Ra/226Ra activity ratios (â‰1) in the coal samples. 226Ra and 228Ra activities correlate with 238U and 232Th activities, respectively, and 226Ra activities correlate well with 210Pb activities across all coal samples. We used measured NORM activities and ash yields in coals to model the activities of CCRs from all U-rich coals analyzed in this study. The activities of measured and modeled CCRs derived from U-rich coals exceed the standards for radiation in building materials, particularly for CCRs originating from coals with U > 10 ppm. Since beneficial use of high-U Chinese CCRs in building materials is not a suitable option, careful consideration needs to be taken to limit potential air and water contamination upon disposal of U- and Ra-rich CCRs.
UR - http://www.scopus.com/inward/record.url?scp=85035355334&partnerID=8YFLogxK
U2 - 10.1021/acs.est.7b03473
DO - 10.1021/acs.est.7b03473
M3 - Article
AN - SCOPUS:85035355334
VL - 51
SP - 13487
EP - 13493
JO - Environmental Science & Technology
JF - Environmental Science & Technology
SN - 0013-936X
IS - 22
ER -